CN107591623A - A kind of broadband based on uncoupling metallic walls, large-angle scanning phased array antenna - Google Patents

Abstract

The present invention discloses a kind of broadband based on uncoupling metallic walls, large-angle scanning phased array antenna, belongs to Radar Technology, wireless communication technology field.The antenna upper two layers medium substrate to fit, layer dielectric substrate in including, for layer dielectric base lower surface covered with metal floor, upper surface is printed with micro-strip transition line；Upper layer medium substrate upper surface is printed with Q-RING paster；Middle level medium substrate upper surface is printed with dipole metal patch；Coaxial fitting inner core passes through layer dielectric substrate connection micro-strip transition line, and micro-strip transition line other end connection parallel wire is fed to antenna；The metallic walls or becket of uncoupling effect are provided between the middle layer dielectric substrate.The present invention has the characteristics of working band is wide, scanning angle is big, low section is easily conformal, available for the radar and communication system for needing low section, broadband and wide-angle scanning range.

Description

A Broadband, Wide-Angle Scanning Phased Array Antenna Based on Decoupled Metal Walls

technical field

The invention belongs to the technical fields of radar technology and wireless communication, and in particular relates to a phased array antenna based on a decoupling metal wall, in particular to wide-band and wide-angle scanning, and is suitable for microwave, millimeter wave and other radar and communication systems.

Background technique

Over the past few decades, broadband, wide-angle scanning phased array antennas have received widespread attention in the military and commercial fields, and are often used in systems such as broadband radar, satellite communications, and radio astronomy. The demand for multifunctional (surveillance, identification, and target tracking) systems on military airborne platforms has also promoted the development of broadband, wide-angle phased array antennas. In this application, small space is the main limitation of antenna design, so it is very beneficial to achieve broadband and wide-angle scanning under a single antenna array aperture. In the traditional broadband and wide-angle scanning phased array antenna design method, firstly, in order to avoid grating lobes when scanning to a large angle, the spacing between antenna elements must be controlled within half a wavelength of the high-frequency end; secondly, the size of the antenna array elements should also be Less than half the wavelength of the high-frequency end, the limitation of the size of the antenna element also increases the difficulty of broadband design. Finally, in the case of small array element spacing (less than half a wavelength at the high frequency end), the mutual coupling between array elements becomes very strong, which will seriously affect the impedance and radiation characteristics of the unit itself. Therefore, even if the antenna array unit obtains a good broadband impedance matching at the side-firing angle, the active impedance of the array antenna unit will change drastically with the scanning angle due to mutual coupling, resulting in a serious mismatch of the array elements in the case of large-angle scanning. . Therefore, how to suppress the mutual coupling between array elements has always been the biggest challenge in the design process of traditional phased array antennas.

In the past ten years, relevant scholars in the field of international antennas have proposed a new idea of using strong coupling antenna elements to realize broadband phased array antennas. The theoretical basis of this idea can be traced back to the continuous current surface theory proposed by Wheeler in 1965. The radiating arms of adjacent dipole units are connected through an interdigitated capacitor structure, and the capacitive reactance added by the interdigitated structure effectively offsets the inductive reactance loading of the ground. Due to the compact arrangement of the antenna array elements and the strong coupling with each other, the current distribution on the dipole unit is almost constant, which effectively expands the bandwidth and verifies the continuous current surface theory. However, in the state of strong mutual coupling, the strong mutual coupling effect of the antenna makes the state change greatly when scanning at a large angle compared with that when scanning sideways, causing large fluctuations in its own active impedance, and it is difficult for the antenna to scan at a large angle. Moreover, the profile of the strong mutual coupling antenna is relatively high, about half the wavelength of the high-frequency end or greater than half the wavelength of the high-frequency end, which is not conducive to the integration and conformality of the antenna and the platform.

To sum up, it is difficult for traditional phased array antennas to have the capability of wide-band and wide-angle scanning at the same time, and the strong-coupling dipole antenna array using coupling also has the defects of difficulty in large-angle scanning and high profile integration. The present invention proposes at these key problems just.

Contents of the invention

The purpose of the present invention is to provide a wide-band phased array antenna with a low profile and easy conformality, which uses metal walls to reduce mutual coupling between units to achieve large-angle scanning.

In order to achieve the above object, the present invention adopts the following technical solution: a wide-band, wide-angle scanning phased array antenna based on decoupling metal walls, including a middle and upper layer of dielectric substrates and a lower layer of dielectric substrate, the lower layer The lower surface of the dielectric substrate is covered with a metal floor, and the upper surface is printed with a microstrip gradient line; the upper surface of the upper dielectric substrate is printed with a square ring patch; the upper surface of the middle dielectric substrate is printed with a dipole metal patch; coaxial The inner core of the joint passes through the lower dielectric substrate to connect to the microstrip gradient line, and the other end of the microstrip gradient line is connected to the parallel double wire to feed the antenna; it is characterized in that: a metal wall for decoupling is arranged between the middle and lower dielectric substrates , and the metal wall penetrates the lower dielectric substrate and connects to the metal floor.

Further, a vertical metal strip perpendicular to the metal wall and functioning as impedance matching is arranged under the middle dielectric substrate.

Further, the metal wall may also be a metal ring structure disposed under the middle dielectric substrate, and the metal ring is not in contact with the lower dielectric substrate.

When the antenna array is working, a continuous current is formed on the dipole metal patch 109, and according to Wheeler's continuous current surface theory, the working bandwidth of the antenna array is effectively increased. The vertical metal strip 106 and the upper dielectric substrate 104 printed with the square ring patch 107 play the role of impedance matching, effectively ensuring that the antenna has good scanning capability within the working bandwidth. The metal wall 105 ensures large-angle scanning performance by reducing mutual coupling between adjacent antenna elements.

Further, the metal ring 201 may also be used equivalently to the role played by the metal wall 105 , a key component in the broadband and wide-angle scanning phased array antenna based on the decoupling metal wall. This is also a form included in the present invention, and Fig. 3 shows the specific structure.

The beneficial effect of the invention is that the use of the decoupling metal wall makes it possible for the wide-band antenna to scan at a large angle, and has the advantages of low profile and easy conformal integration.

Description of drawings

FIG. 1 is a schematic structural diagram of the 6×16 broadband and wide-angle scanning phased array antenna based on decoupling metal walls described in Embodiment 1.

FIG. 2 is a schematic diagram of the basic antenna unit of the broadband, wide-angle scanning phased array antenna based on the decoupling metal wall described in Embodiment 1. FIG.

FIG. 3 is a schematic diagram of a basic antenna unit using a metal ring instead of a metal wall as described in Embodiment 1. FIG.

FIG. 4 is a simulation result of the active voltage standing wave ratio of the E plane of the basic antenna unit described in Embodiment 1. FIG.

FIG. 5 is a simulation result of the H-plane active voltage standing wave ratio of the basic antenna unit described in Embodiment 1. FIG.

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the implementation manners and accompanying drawings.

Example 1

The wide-band, wide-angle scanning phased array antenna based on the decoupling metal wall of this embodiment adopts a 6×16 planar array form, as shown in FIG. 1 . It includes the lowermost metal floor 101, the lower dielectric substrate 102 printed with microstrip gradient lines, the middle dielectric substrate 103 printed with dipole metal patches, and the upper dielectric substrate 104 printed with square rings for matching. FIG. 2 is a schematic diagram of a basic antenna unit in FIG. 1 . The lowermost metal floor 101 is an aluminum plate with a thickness of 4 mm. The relative dielectric constant of the lower dielectric substrate 102 is 2.2, and the thickness is 0.254 mm. Microstrip gradient lines 110 are printed on it. The relative permittivity of the middle layer dielectric substrate 103 is 2.2, the thickness is 1mm, and the dipole metal patch 109 is printed on it. The upper dielectric substrate 104 has a relative permittivity of 3 and a thickness of 4mm, on which a square ring patch 107 is printed. Three vertical metal strips 106 are located below the middle dielectric substrate 103 . The metal wall 105 is located between the lowermost metal floor 101 and the middle dielectric substrate 103 and has a thickness of 1 mm. The inner core 111 of the coaxial joint passes through the opening on the lower metal floor 101 and is connected to the microstrip gradient line 110 , and on the other side of the microstrip gradient line, it is connected to the parallel pair of lines 108 to feed the antenna.

As shown in Figure 1, 6 antenna elements are arranged along the H plane with a unit spacing of 33 mm, and 16 antenna units are arranged along the E plane with a unit spacing of 33 mm. The array profile height is 21 mm. In this example, the designed working frequency band is 1.5-4GHz, the unit size is 0.44 times of the high-frequency 4GHz wavelength, and the array profile height is only 0.28 times of the high-frequency 4GHz wavelength, which has the characteristics of low profile.

Fig. 4 and Fig. 5 respectively show the simulation results of the active voltage standing wave ratio of the E plane and the H plane of the basic antenna unit in this embodiment varying with frequency at different scan angles. It can be seen from Figure 4 that within the scanning range of ±75°, the impedance bandwidth of the active voltage VSWR less than 2.5 reaches 91%. It can be seen from Figure 5 that within the scanning range of ±45°, the active voltage The impedance bandwidth of the VSWR less than 2.5 is up to 91%, realizing the broadband and wide-angle scanning of the phased array antenna.

Example 2

Specifically, a planar array of any size can be formed by extending each basic antenna unit in a two-dimensional direction. Other structures are the same as those described in detail in Example 1.

The foregoing descriptions of the present invention and its embodiments are provided to those skilled in the art of the invention and are to be considered illustrative rather than restrictive. Engineers and technicians can implement specific operations based on the ideas in the claims of the invention, and can make various changes in form and details without departing from the spirit and scope of the present invention defined by the appended claims. Variety. All of the above should be considered as the scope of the present invention.

Claims (3)

1. A wide-band, wide-angle scanning phased array antenna based on decoupling metal walls, comprising a dielectric substrate with two upper and middle layers attached together, and a lower dielectric substrate, the lower surface of the lower dielectric substrate is covered with a metal floor, and the upper and lower dielectric substrates are covered with a metal floor. The surface is printed with a microstrip gradient line; the upper surface of the upper dielectric substrate is printed with a square ring patch; the upper surface of the middle dielectric substrate is printed with a dipole metal patch; the inner core of the coaxial connector passes through the lower dielectric substrate to connect the micro With tapered line, the other end of the microstrip tapered line is connected to parallel double wires to feed the antenna; it is characterized in that: a metal wall for decoupling is arranged between the middle and lower dielectric substrates, and the metal wall penetrates the lower dielectric substrate to connect to the metal floor. 2. A broadband, wide-angle scanning phased array antenna based on a decoupling metal wall as claimed in claim 1, characterized in that: the metal wall can also be a metal ring structure arranged under the middle dielectric substrate, and The metal ring is not in contact with the underlying dielectric substrate. 3. A broadband, wide-angle scanning phased array antenna based on decoupling metal walls as claimed in claim 1 or 2, characterized in that: the bottom of the middle dielectric substrate is provided with an impedance matching function perpendicular to the metal wall vertical metal strips.